1. Field of the Invention
The invention relates to a method in connection with coating of an optical fibre or the like, wherein a first fibre or the like is directed from a fibre pay-off forward in the process via a press head forming the coating, and when the first fibre or the like ends, a new fibre or the like is guided to the press head and through it. The invention also relates to an arrangement in connection with an optical fibre or the like.
2. Description of Related Art
When a fibre ends in an optical fibre coating process, such as a tight buffer process, also the buffer supplied from the press head breaks in prior art solutions. In such a situation, the line operator has been forced to manually thread the buffer again through the line, in other words to restart the process. In such a restart the amount of wasted fibre rapidly increases to several dozens of meters, which also raises the costs due to the loss of material. Another problem has been that manual threading is laborious and slow, which further increases the costs and reduces the degree of use of the line. Further, manual threading is also an obvious security risk.
The purpose of the invention is to provide a method and an arrangement which eliminate the prior art drawbacks. This is achieved with the method and arrangement according to the invention. The method according to the invention is characterized in that the new fibre or the like is directed to the vicinity of the press head in advance, so that when the first fibre or the like ends, a roll device grips both the first fibre and the new fibre or the like so that both fibres or the like are caught between freely rotating rolls of the roll device, whereupon the tail of the first fibre or the like makes the rolls of the roll device rotate, whereafter the rotational movement of the rolls pushes the new fibre or the like to the press head at a speed equal to that of the line. The arrangement according to the invention is, in turn, characterized in that the arrangement comprises a holder and a roll device comprising two freely rotating rolls, which have two positions: a first position where the rolls are spaced apart and a second position where the rolls are pressed together, the rolls being arranged before the press head at opposite sides of the fibre line passing through the press head, and the holder being arranged to keep the end of the new fibre or the like near the press head such that the end of the new fibre or the like is positioned between the rolls placed in the first position of the roll device as the first fibre or the like travels from between the rolls of the roll device to the press head, and that when the first fibre or the like ends, the rolls of the roll device are arranged to move into the second position so that both the first fibre and the new fibre or the like remain between the rolls and the tail of the first fibre or the like makes the rolls rotate, and the holder is arranged to open, whereupon the rotational movement of the rolls pushes the new fibre or the like to the press head at a speed equal to that of the line.
A primary advantage of the invention is that it avoids the time-consuming and laborious manual restart, wherefore the amount of wasted fibre remains as small a possible. The invention thus provides economic advantages due to lower fibre costs and an improved degree of use of the line. Further, the structure of the arrangement according to the invention is simple and reliable. The invention also improves the operational safety of the line since the operator does not have to thread a fibre manually through the entire line or to feed a new fibre into the process during the operation of the line.